From WO 2005/071342 A1 a generic plate heat exchanger is known, having a plurality of individual heat exchanger plates, which are joined to each other in a sealed manner, in particular are soldered to each other. As upper closure here a cover plate is provided, which on at least one site has a downwardly directed curvature or respectively recess and engages with this recess into an opening of a heat exchanger plate arranged beneath. A disadvantage in the presented prior art is, however, that the cover plate per se and in particular the recesses have only a comparatively poor stability.
The present invention is therefore concerned with the problem of providing for a plate heat exchanger of the generic type an improved or at least an alternative embodiment, which is distinguished in particular by an increased stability with respect to a cover plate.